nRF5340 QSPI flash

[Jason]

Hi:

SW: NCS v2.5.0

HW: nRF5340 + flash gd25q256e 

To reduce the power consumption of the QSPI flash, we have two approaches.

1. cut off the QSPI flash's power when the product is in sleep mode (the power can be turned on/off by an LDO)

2. always keep the power of the QSPI flash, and put the flash into deep power down mode when the product is in sleep mode.

unfortunately, both of these two approaches have problems.

for approach 1, when turning on the power again, and initiating the QSPI and XIP again, the XIP doesn't work.

e.g 

 printk("#2Address of %x value %x\n", 0x10000008, *(uint32_t *)0x10000008);

 printk("#2Address of %x value %x\n", 0x10000040, *(uint32_t *)0x10000040);

 the values are wrong. 

for approach 2，

put the QSPI flash into deep power down mode by calling pm_device_action_run(flash_dev, PM_DEVICE_ACTION_SUSPEND);

this works, we can see the power consumption is reduced.

wake up the flash from deep power down mode by calling pm_device_action_run(flash_dev, PM_DEVICE_ACTION_RESUME);

but this function return -EIO, and it is caused by the nrfx_qspi_init return NRFX_ERROR_TIMEOUT.

if we don't put the flash into deep power-down mode, every thing is OK.

below is the QSPI configuration 

&qspi {
	status = "okay";
	pinctrl-0 = <&qspi_default>;
	pinctrl-1 = <&qspi_sleep>;
	pinctrl-names = "default", "sleep";
	gd25q256: gd25q256e@0 {
		compatible = "nordic,qspi-nor";
		reg = <0>;
		/* GD25Q256 supports only pp(cmd 02H) and pp4o(cmd 32H) */
		writeoc = "pp4o";
		/* GD25Q256 supports all readoc options */
		readoc = "read4io";
		sck-frequency = <8000000>;
		jedec-id = [c8 40 19];
		sfdp-bfp = [/*read the sfdp-bfp by jesd216 sample(zephyr\samples\drivers\jesd216)*/
			e5 20 f3 ff  ff ff ff 0f  44 eb 08 6b  08 3b 42 bb
			ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
			10 d8 00 ff  d6 39 a5 fe  83 1f 15 51  ec 62 16 33
			7a 75 7a 75  04 bd d5 5c  00 06 64 00  08 50 00 01
		];
		size = <268435456>;
		has-dpd;
		t-enter-dpd = <40000>;
		t-exit-dpd = <45000>;
		enter-4byte-addr = <0x01>;
		address-size-32;
	};
};

Do you have any ideas on this issue?

Thanks!

[AHaug]

Hi,

I've discussed this internally with my colleagues and this is what we suggest for now

Since this is an issue causing some boards to fail and not all we need to some more information regarding the failure rate and more. 

If you've not done so already could you make an estimate over how many boards this fails on and how many boards this error does not trigger on?

I'm sure you've also considered this, but the most plausible thing causing the inconsistent fault is soldering issues. Have you verified if this is the cause? If not, we need to eliminate that reason before diving into software

Could you perform measurements using a logic analyser or scope boards with and without the fault? 

Let me know more about these items and I'll escalate it internally asap if the issue can't be pinned to hardware/faulty soldering

Kind regards,
Andreas

[Jason]

Hi,

sorry for the delay

because this product is just in the prototype phase, we just have 10 samples at this moment, two samples work, one works sometimes, and the others never work.

AHaug said:

Could you perform measurements using a logic analyser or scope boards with and without the fault? 

As I said, the error already occurred before the nrf5340 sent the wakeup cmd to the QSPI flash. 

According to the source code, line 50 'err = nrfx_qspi_init(&dev_config->nrfx_cfg,qspi_handler,dev_data);'

return -EIO.

static int qspi_nor_pm_action(const struct device *dev,
			      enum pm_device_action action)
{
	struct qspi_nor_data *dev_data = dev->data;
	const struct qspi_nor_config *dev_config = dev->config;
	int ret;
	nrfx_err_t err;

	if (pm_device_is_busy(dev)) {
		return -EBUSY;
	}

	switch (action) {
	case PM_DEVICE_ACTION_SUSPEND:
#ifndef CONFIG_PM_DEVICE_RUNTIME
		/* If PM_DEVICE_RUNTIME, we don't uninit after RESUME */
		ret = qspi_device_init(dev);
		if (ret < 0) {
			return ret;
		}
#endif

		if (dev_data->xip_enabled) {
			return -EBUSY;
		}

		if (nrfx_qspi_mem_busy_check() != NRFX_SUCCESS) {
			return -EBUSY;
		}

		ret = enter_dpd(dev);
		if (ret < 0) {
			return ret;
		}

		nrfx_qspi_uninit();
		ret = pinctrl_apply_state(dev_config->pcfg,
					  PINCTRL_STATE_SLEEP);
		if (ret < 0) {
			return ret;
		}
		break;

	case PM_DEVICE_ACTION_RESUME:
		ret = pinctrl_apply_state(dev_config->pcfg,
					  PINCTRL_STATE_DEFAULT);
		if (ret < 0) {
			return ret;
		}
		err = nrfx_qspi_init(&dev_config->nrfx_cfg,
				     qspi_handler,
				     dev_data);
		if (err != NRFX_SUCCESS) {
			return -EIO;
		}

		ret = exit_dpd(dev);
		if (ret < 0) {
			return ret;
		}

#ifndef CONFIG_PM_DEVICE_RUNTIME
		/* If PM_DEVICE_RUNTIME, we're immediately going to use the device */
		qspi_device_uninit(dev);
#endif
		break;

	default:
		return -ENOTSUP;
	}

	return 0;
}

Please have a look at my analysis below 

Jason said:

it is caused by the qspi_ready_wait() return NRFX_ERROR_TIMEOUT. 

the qspi_ready_wait function is waiting for the  EVENTS_READY.

According to the datasheet, this EVENTS_READY can be generated by setting TASKS_ACTIVATE.

In nrfx_qspi_init(), this is done by nrf_qspi_task_trigger(NRF_QSPI, NRF_QSPI_TASK_ACTIVATE); 

so the root cause is that the EVENTS_READY is not generated after  TASKS_ACTIVATE was activated.

I think we need to know what is the condition to generate the EVENTS_READY.

I didn't find any available information about this in the datasheet 

[AHaug]

Hi,

Jason said:

because this product is just in the prototype phase, we just have 10 samples at this moment, two samples work, one works sometimes, and the others never work.

This further strengthens the theory that this is a hardware issue and not a software issue

Jason said:

As I said, the error already occurred before the nrf5340 sent the wakeup cmd to the QSPI flash. 

This does not change the need for us to know more about the analysis requested as well as to look further into the hardware. 

It could also be a design issue. Have you at any point had you designed reviewed? If not, I would recommend that you can create a new case and refer to the Devzone ID of this one (320224) as reference and request a design review from one of our hardware engineers so they can have a look as if there is any issues there.

Kind regards,
Andreas

[Jason]

Thanks, I will let our HW team contact you by email.

[AHaug]

Hi

Happy to help.

You can request a HW review through Devzone instead of through email. If you have anything confidential you can create a private case and we'll assign it to an available hardware engineer from there.

Kind regards,
Andreas